This invention relates to a packaged film and a method of processing the film such that, after imagewise exposure, the film is capable of being color developed either (1) by sequential immersion of the film in a wet-chemical multi-tank process at a temperature of 60xc2x0 C. or less by immersion in a phenylenediamine-containing developer solution or its equivalent, followed by desilvering in one or more subsequent solutions, to obtain a color negative film with the silver and silver halide removed from the film, or alternatively, (2) by thermal treatment of the film, by heating the film at a temperature greater than 80xc2x0 C., preferably greater than 100xc2x0 C., more preferably greater than 120xc2x0 C., without liquid saturation of the film, preferably in an essentially dry process without the addition of any aqueous solutions. When dry developed, the imaged film may be electronically scanned without removing the silver and/or silver-halide.
With the remarkable advances in the fields of solid-state imaging devices and various hard-copy printing technologies made in recent years, the comparison between electronic imaging systems and the silver-halide photographic system has become a frequent subject of discussion. Nevertheless, the superiority of the silver halide photographic system with respect to high sensitivity and high image quality, particularly with respect to affordable consumer products, will not be threatened for some time in the future. One particular shortcoming of the silver-halide system, however, in comparison to electronic imaging systems is that the photographic element requires a so-called wet-development process that typically requires substantial volumes of solutions such as developing, fixing, and bleaching solutions. For the people engaged in the development of silver-halide photographic techniques, the development of a xe2x80x9cdryxe2x80x9d development process for the silver-halide color photographic system has been a goal for many years.
A dry development process can be accomplished by the use of photothermographic elements described in Research Disclosure 17029 (Research Disclosure I). Generally, in these kinds of systems, development occurs by reduction of silver ions in the photosensitive silver halide to metallic silver as in conventional non-thermal systems, but the developing agent is contained within the element, so that it is unnecessary to immerse the photographic element in an aqueous solution containing a developing agent. Various types of photothermographic elements have been proposed and patented. Research Disclosure I discloses a type A and a B photothermographic system. Type B elements, the subject of this invention, contain in reactive association a binder, a photosensitive silver halide (prepared in situ or ex situ) and an oxidation-reduction image forming combination comprising (1) a metallic salt or complex of an organic compound as an oxidizing agent, and (2) an organic reducing agent or developing agent. A problem has been to achieve a commercially viable system that produces a quality of image comparable, in the eyes of the average film consumer, to traditional silver-halide film.
A practical color photothermographic system for general use with respect to consumer cameras would have significant advantages. Such film might be amenable to development at kiosks, with the use of dry equipment. Thus, it is envisioned that a consumer could bring an imagewise exposed photothermographic film, for development and printing, to a kiosk located at any one of a number of diverse locations, optionally independent from a wet-development lab, where the film could be developed and printed without any manipulation by third-party technicians. It is also envisioned that a consumer might be more prone to owning and operating such film development equipment in a home, particularly if it was dry and did not involve the use of complex chemicals. Thus, the development of a successful photothermographic system could open up new opportunities for greater convenience and speed of development, even immediate development in the home for a wider cross-section of consumers.
In order to maintain the dry aspect of a photothermographic system, various possibilities exist. One, for example, is to fix/bleach (remove the silver and silver halide) in effect by a diffusion transfer. See, for example EP 0762 201 to Matsumoto et al assigned to Fuji Photo Film Co. The patent is primarily addressed to dye-diffusion processes requiring some amount of water, albeit relatively small amounts of aqueous solutions not containing complex chemicals. Although disclosing an example of a dry system, it may not provide acceptable image quality or may not be sufficiently enabled for practical or wide-spread use, since commercialization of a dry system has not taken place. On the other hand, in view of the advance of scanning technologies, it has now become natural and practical for photothermographic color film such as disclosed in EP 0762 201 to be scanned, which can be accomplished without the necessity of removing the silver or silver-halide from the negative, although special arrangements for such scanning can be made to improve its quality. See, for example, Simons U.S. Pat. No. 5,391,443.
Dry photothermographic film elements would offer significant advantages in processing ease and convenience, since they could be developed only by the application of heat and require no wet processing solutions. However, this advantage comes at a price, since the films must be developed in a thermal processor that may not be (at least initially) as available as conventional C-41 processors, which are widely available as an mature industry standard. The unavailability of thermal processors and associated equipment can hinder the adoption of dry photothermographic films by the consumer. For example, accessibility of thermal processors or processing may vary with the geographical location of the consumer. Photothermographic films that can also be processed by C-41 chemistry or the like overcome this disadvantage or problem. Photothermographic films that are backwards compatible permit the consumer to enjoy the benefits unique to thermal processing (kiosk processing, low environmental impact, and the like) when thermal processing is accessible, but also allow the consumer to take advantage of the current ubiquity of C-41 processing when thermal processing may not be accessible.
It would be desirable if a dry photothermographic system could be made that was backwards compatible for use with a conventional wet-development process. Applicants have encountered serious obstacles to obtaining a dry photothermographic system that is backwards compatible. Such photothermographic systems, in which an organic silver salt plays the role of a silver ion source but does not function as the photosensor and memory, was not found not to be readily backwards compatible because of the antifoggants typically contained and thought necessary in such film. In other words, because such photothermographic films contain blocked developers, and in the absence of processing solutions, require high temperatures for development, agents for preventing fog or increased Dmin during thermal processing are believed necessary, which agents would block development in conventional processing, for example, C-41 processing.
Japanese kokai patent publication 10-78638 (Mar. 24, 1998) claims the use of a color photographic element that is backwards compatible by means of using a special combination of two yellow dye couplers with an unblocked ballasted sulfonamidophenol or sulfonyl hydrazide type developing agent. The pair of yellow dye couplers consist of one having a detachable cationic group and one having a detachable anionic group, the latter coupler preferably also containing a dye suppressant. It was found that, in the absence of one of the couplers, the color sensitivity during conventional wet-development was relatively poor, and that in the absence of the other of the two couplers, the granularity during conventional wet-development was relatively poor. As mentioned above, the photothermographic developing agent in Japanese kokai patent publication 10-78638 to Matsumoto et al was unblocked, and this fact may have adversely affected wet-development processing with conventional combinations of couplers and developing agents. Another disadvantage of the ballasted sulfonamidophenol developing agents or ballasted sulfonylhydrazide developing agents in kokai 10-78638 is that they generally react with couplers to form dyes of low extinction or to form dyes which differ in hue from those formed with phenylenediamine color developing agents, resulting in unwanted color variations. This fact also limits the ability of the developed color negative image, after scanning, to provide visually editable and previewable images.
In order to be acceptable for commercial application, it is necessary that a photothermographic system be stable before exposure, while avoiding desensitizing of the silver halide during storage, resulting in increased fog and/or decreased Dmax after development. At the same time, the system must capable of sufficiently fast kinetics (including unblocking of the developing agent) when the exposed film is being developed by thermal activation. In the case of the same photothermographic film designed for alternatively (at the discretion of the consumer) traditional wet-processing or dry thermal processing, it is surmised that another requirement might be that the components in the photothermographic film, designed exclusively for the dry photothermographic development (for example the blocked developing agent and antifogging agents) do not adversely affect or interfere with obtaining the results otherwise achieved by traditional wet-processing. In the case of sequential development, in which an initial dry photothermographic film is followed by a conventional wet process, the requirements are somewhat different. The photothermographically developed film image must not be affected by the development step in the traditional wet-processing, but must be effectively subjected with subsequent post-development steps such as fixing and bleaching.
A photothermographic color film, in which a silver-halide-containing color photographic element after imagewise exposure can be developed merely by the external application of heat by thermal treatment of the film, by heating the film at a temperature greater than 80xc2x0 C., without liquid saturation of the film, preferably in an essentially dry process without the addition of any aqueous solutions, but which same film is also amenable to development in an automated kiosk, preferably not requiring third-party manipulation, would have significant advantages. Assuming the availability and accessibility of such kiosks, such photothermographic films could potentially be developed at any time of day, xe2x80x9con demand,xe2x80x9d in a matter minutes, without requiring the participation of third-party processors, multiple-tank equipment and the like. Such photothermographic processing could potentially be done on an xe2x80x9cas neededxe2x80x9d basis, even one roll at a time, without necessitating the high-volume processing that would justify, in a commercial setting, equipment capable of high-throughput. The kiosks thus envisioned would be capable of heating the film to develop a negative color image and then subsequently scanning the film on an individual consumer basis, with the option of generating a display element corresponding to the developed color image.
The invention relates to a color photographic film element comprising a support bearing at least two (preferably three) light-sensitive silver-halide emulsion units each having in reactive association at least one dye-forming coupler, a blocked color developing agent, a photosensitive silver halide and an oxidation-reduction image forming combination comprising (a) at least one metallic salt or complex of an organic compound as an oxidizing agent, and (b) an organic reducing agent or developing agent. The application of heat converts the latent color-developing agent to reactive form. In one embodiment, the photothermographic element is a multilayer, multicolor element having red, green and blue color recording units each formed from like light sensitive layers respectively having cyan dye-forming, magenta dye-forming and yellow dye-forming couplers. In all cases, the latent color developing agent can be in the same layer as a light-sensitive emulsion or it can be in a light insensitive layer. This photographic film is designed to enable a single film stock to be developed in either (1) a conventional wet-chemical process, for example a C-41 deep-tank process, or (2) a dry process. For example, an individual consumer, at his or her discretion, could potentially take the film to a kiosk to be thermally developed, or alternatively, submit the film to a wet-processing lab. Thus, depending on various factors, including the availability of thermal processing facilities in a given geography over a give period of time, it can be expected that, a portion of such film will, in fact, be developed by a conventional wet-chemical process, and a portion of such film will be developed by a dry thermal process.
The feature of the present photothermographic films that make them backwards compatible is the complexing of the fog inhibitor as its silver ligand. This silver complex has little inhibitory effect on the chemical development that occurs in conventional C-41 processing.
In one embodiment of the present invention, a packaged photographic film element has at least two (preferably three) light-sensitive layers which have their individual sensitivities in different wavelength regions, each of the layers comprising a light-sensitive silver-halide emulsion, a binder, a dye-providing coupler, and a blocked developing agent. The package (inclusive of its package insert) includes indicia indicating that the consumer may direct the film to be alternatively processed and developed in either of two routes. These two routes correspond (at least in fact by means of consumer processing selection, if not explicitly stated) to, respectively (1) a conventional wet-chemical processing, for example, a C-41 process, and (2) a dry thermal process utilizing essentially no aqueous solutions or externally applied developing agent.